Elmer S. Riggs, a vertebrate paleontologist appointed shortly after The Field Museum's opening, became the new Geology Department's second curator, and assembled the nucleus of the vertebrate paleontology collections. Riggs collected dinosaurs from the Jurassic and Cretaceous of Colorado, Wyoming, Montana, and Alberta, Canada. He led many expeditions to the Western US in search of fossil mammals. He most lasting legacy is the fruits of two multi-year expeditions Riggs led to South America where he amassed an outstanding Cenozoic mammal collection from Bolivia and Argentina.

Elmer Riggs and excavation party members, 1927 (c) The Field Museum CSGEO69625

Henry W. Nichols, the second chair, specialized in mineralogy. He was followed by Sharat K. Roy, who studied in his native India, London, and Illinois, and led a number of museum expeditions, including those to Baffin Land and Labrador in 1927-1928.

Bryan Patterson, on staff from 1926 to 1955, published extensively on Riggs' collection of South American fossil mammals, and made several major collections in the United States, including those from the Piceance Basin, one of the first significant Paleocene fossil vertebrate faunas. His collection and studies on the Trinity Cretaceous mammals of "metatherian-eutherian grade" from north Texas was a major contribution to mammalian paleontology.

Rainer Zangerl became head of the department in 1962 after serving seventeen years as curator of fossil reptiles. Zangerl extended his interest to Pennsylvanian paleoecology, and co-authored (with Eugene Richardson) a now classic memoir on paleoecology of Pennsylvanian black shales. In 1965, during Zangerl's tenure the paleontology collections expanded dramatically when the University of Chicago Walker Museum Collections were transferred to the Field Museum. Zangerl was succeeded in 1974 by Edward J. Olsen, who came to the museum in 1960 after teaching at Case Institute of Technology and Western Reserve. David M. Raup joined the geology staff as department chair in 1978, following faculty positions at the California Institute of Technology, Johns Hopkins, the University of Rochester, and the University of Chicago. John R. Bolt became department chair in 1981, following a period in which Bertram G. Woodland was acting chair. Bolt received his doctorate from the University of Chicago, and joined the Museum in 1972 after several years of teaching at the University of Illinois at Chicago.

John Bolt, 1997 (c) The Field Museum GN88434_7c, photographer John Weinstein

Peter R. Crane, now one of the world’s leading peleobotanists, joined the Department in 1982 and served as Chair from 1990-1992 before taking a more senior administrative position. John J. Flynn, joined Field Museum's geology staff in January, 1988, following several years as a professor in the Department of Geological Sciences at Rutgers University. He served as chair from 1992-2000. Olivier Rieppel, MacArthur Curator of Fossil Reptiles, came to the department from a position at the Paleontological Institute and Museum of the University of Zurich and later served as chair from 2001-2008. His research has spanned the Mesozoic diversification of reptiles, including the origins of snakes and turtles, as well as history and philosophy of systematic biology. The current chair, Peter Makovicky, is a leading researcher on the evolutionary history of dinosaurs. He joined the staff in 2001 after graduating from Columbia University / American Museum of Natural History.